tesserahub/sympy — comment on commit dd86ef42b3fb283084d41da4cf7b608c6ecb3eed
File: sympy/stats/crv.py line 244
By mrocklin:

It is confusing, I agree. It's also what makes the most sense to me. There are times when you will have different random variables on the same symbol and you'll want to compare them - for this reason I'm not a fan of the dummy idea. We could have them print differently, true. I have X print x because, when modeling uncertainty problems it tends to make things look like the underlying mathematical model. This provides a conceptual divide between mathematical modeling and uncertainty quantification - the modeling is left untouched by the addition of uncertainty.

However, while this all makes sense to me, it obviously doesn't make sense to others and even if I think my way is the one-true-way I still have to admit that this confusion is a serious issue. Sometime next week I'm planning to add a bit to the stats documentation page. Let me see if I can come up with an clear and motivating reason to do it the way it's currently done. If I can't do that then perhaps we should look at other options.

How densities are represented is somewhat arbitrary at the moment. Different types (continuous, finite, multivariate) have entirely different density representations (symbol/expr tuple, dict, matexpr tuple). This could definitely be improved.